我得到了这个任务：
“编写一个程序（Blueberry.java），它使用while循环打印整数1到100，每行一个数字，并将数字的字段宽度设置为3.当一个数字可被3整除时，打印”蓝色“在同一行上，并用空格分隔。按照相同的格式，当一个数字可被5整除时，打印”Berry“;当一个数字可被15整除时，打印”Blueberry“。注意一个数字可被15整除也可以被3和5整除。在这种情况下，只应打印“蓝莓”。应在第一行打印一条消息“以下是来自一个循环”。三条消息，一条打开应该打印每一行，分别报告“Blue”，“Berry”和“Blueberry”的总数。最后，在同一个程序中，添加一个for循环和一个do ... while循环：每个完成相同的任务while循环。“ 我已经找到了while循环和for循环，但是我遇到了do ... while循环的问题。
这是我到目前为止所做的：
import java.util.Scanner;
public class Blueberry {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("The following is from a while loop: ");
int blueCount = 0;
int berryCount = 0;
int blueberryCount = 0;
int i = 1;
while(i <= 100){
if(i % 3 == 0 && i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Blueberry");
blueberryCount++;
}
else if(i % 3 == 0) {
System.out.printf("%3d %s\n", i, "Blue");
blueCount++;
}
else if(i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Berry");
berryCount++;
}
else {
System.out.printf("%3d\n", i);
}
i++;
}
System.out.printf("There are %d Blues. \n", blueCount);
System.out.printf("There are %d Berries. \n", berryCount);
System.out.printf("There are %d Blueberries. \n", blueberryCount);
System.out.println();
blueCount = 0;
berryCount = 0;
blueberryCount = 0;
System.out.println("The following is from a for loop: ");
for (i = 1; i <= 100; i++) {
if(i % 3 == 0 && i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Blueberry");
blueberryCount++;
}
else if(i % 3 == 0) {
System.out.printf("%3d %s\n", i, "Blue");
blueCount++;
}
else if(i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Berry");
berryCount++;
}
else {
System.out.printf("%3d\n", i);
}
}
System.out.printf("There are %d Blues. \n", blueCount);
System.out.printf("There are %d Berries. \n", berryCount);
System.out.printf("There are %d Blueberries. \n", blueberryCount);
System.out.println();
blueCount = 0;
berryCount = 0;
blueberryCount = 0;
System.out.println("The following is from a do...while loop: ");
do {
if(i % 3 == 0 && i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Blueberry");
blueberryCount++;
}
else if(i % 3 == 0) {
System.out.printf("%3d %s\n", i, "Blue");
blueCount++;
}
else if(i % 5 == 0) {
System.out.printf("%3d %s\n", i, "Berry");
berryCount++;
}
else {
System.out.printf("%3d\n", i);
}
i++;
}
while (i <= 100);
}
}
and this is what it looks like when I run it:
以下是来自while循环：
1
2
3 Blue
4
5 Berry
6 Blue
7
8
9 Blue
10 Berry
11
12 Blue
13
14
15 Blueberry
16
17
18 Blue
19
20 Berry
21 Blue
22
23
24 Blue
25 Berry
26
27 Blue
28
29
30 Blueberry
31
32
33 Blue
34
35 Berry
36 Blue
37
38
39 Blue
40 Berry
41
42 Blue
43
44
45 Blueberry
46
47
48 Blue
49
50 Berry
51 Blue
52
53
54 Blue
55 Berry
56
57 Blue
58
59
60 Blueberry
61
62
63 Blue
64
65 Berry
66 Blue
67
68
69 Blue
70 Berry
71
72 Blue
73
74
75 Blueberry
76
77
78 Blue
79
80 Berry
81 Blue
82
83
84 Blue
85 Berry
86
87 Blue
88
89
90 Blueberry
91
92
93 Blue
94
95 Berry
96 Blue
97
98
99 Blue
100 Berry
There are 27 Blues.
There are 14 Berries.
There are 6 Blueberries.
以下内容来自for循环：
1
2
3 Blue
4
5 Berry
6 Blue
7
8
9 Blue
10 Berry
11
12 Blue
13
14
15 Blueberry
16
17
18 Blue
19
20 Berry
21 Blue
22
23
24 Blue
25 Berry
26
27 Blue
28
29
30 Blueberry
31
32
33 Blue
34
35 Berry
36 Blue
37
38
39 Blue
40 Berry
41
42 Blue
43
44
45 Blueberry
46
47
48 Blue
49
50 Berry
51 Blue
52
53
54 Blue
55 Berry
56
57 Blue
58
59
60 Blueberry
61
62
63 Blue
64
65 Berry
66 Blue
67
68
69 Blue
70 Berry
71
72 Blue
73
74
75 Blueberry
76
77
78 Blue
79
80 Berry
81 Blue
82
83
84 Blue
85 Berry
86
87 Blue
88
89
90 Blueberry
91
92
93 Blue
94
95 Berry
96 Blue
97
98
99 Blue
100 Berry
There are 27 Blues.
There are 14 Berries.
There are 6 Blueberries.
以下是来自do ... while循环： 101
do ... while循环我做错了什么？
答案 0 :(得分：2)
在开始variable之前，您应初始化int i = 1 do..while loop。
这就是为什么你从[{1}} 101获得i = 101 for的原因。
答案 1 :(得分：0)
一个问题可能是你没有在while循环之后将你的'i'计数器设置为0，所以这对do {} while循环开始为100，因为条件是一次然后检查是否'i '等于或大于100才能停止。
尝试在while循环后将i设置为0
我希望它有所帮助！ ：）
答案 2 :(得分：0)
do-while循环将至少使用1次，然后开始比较... 那与the while和for的区别，也许这就是你的问题
并为您的代码。你没有初始化＆＃39;我＆＃39;变量
参考： http://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
我希望这可以帮助你